Vascular clamp and method for using the same

ABSTRACT

The present invention relates to a vascular clamp assembly. The vascular clamp assembly includes at least one bendable elongated shaft with a proximal part and distal part. A pair of clamping members are located at the distal part of the shaft. The clamp includes means for moving the clamping members between an open position and a clamping position.

This is a divisional of application Ser. No. 09/042,307 filed on Mar.13, 1998 now U.S. Pat. No. 6,036,706. The priority of this applicationis expressly claimed and disclosure is hereby incorporated by reference.

FIELD OF THE INVENTION

This invention relates generally to surgical instruments for temporarilyoccluding a blood vessel during surgical procedures, and moreparticularly to vascular clamps for temporarily occluding a blood vesselduring cardiopulmonary bypass (CPB) to facilitate the performance ofcardiac procedures.

BACKGROUND OF THE INVENTION

To facilitate the reader's understanding of the present invention, theCPB process is generally described below, followed by a description ofthe problems with vascular clamps used during the CPB process in thepast.

The descriptive terms upstream and downstream, when used herein inrelation to the patient's vasculature, refer to directions closer to andfurther from the heart in the arterial system, and the opposite in thevenous system. The terms proximal and distal, when used herein inrelation to instruments, refer to directions closer to and farther awayfrom the operator of the instrument, respectively.

During CPB, it is desirable to provide life-support functions, amotionless, decompressed heart and a dry, bloodless field of view forthe surgeon. In a basic CPB system, oxygen-poor blood is drained bymeans of gravity or is syphoned from the patient's venous circulationand is transported to a pump-oxygenator, commonly known as theheart-lung machine, where the blood is exposed to a gaseous mixture thateliminates carbon dioxide and adds oxygen to the blood. The oxygenatedblood is then returned or perfused into the patient's arterialcirculation for distribution throughout the entire body. This processrequires a venous drainage cannula (or cannulae) to be placed into theright side of the heart (typically the right atrium) or directly in themajor veins (typically the superior vena cava (SVC) and/or inferior venacava (IVC)) or through peripheral vein access sites to drainunoxygenated blood from the patient and deliver it to the heart-lungmachine. Similarly, an arterial or aortic perfusion cannula is placed inthe aorta or another large peripheral artery, such as the common femoralartery, to return or perfuse oxygenated blood to the patient. The heartand lungs of the person can thereby be effectively bypassed, thusallowing the surgeon to operate on a bloodless heart.

The insertion of the arterial (aortic) perfusion cannula is usuallyperformed in the following fashion. After an incision is made in thepatient's chest and the pericardium (the protective sac around theheart) has been entered, two concentric purse string sutures are placedinto the anterior wall of the ascending aorta just proximal to upstreamof the brachiocephalic trunk. A "choker" tube or sleeve is positionedover the trailing ends of the suture threads to act as a tourniquet fortightening the purse string suture. A small incision is then madethrough the wall of the aorta into its lumen in the center of thepurse-string sutures. The aortic perfusion cannula is then quicklyinserted through that incision into the lumen of the aorta, taking careto minimize the escape of blood from the puncture site. The purse stringsutures are then tightened by means of their respective tourniquets toseal the aortic wall around the perfusion cannula in order to preventthe escape of blood from the aorta. Air is then evacuated from theperfusion cannula as it is joined by a connector to the tubing from thepump-oxygenator. A mechanical cross-clamp, i.e., vascular clamp, isplaced on the ascending aorta just downstream of the aortic root andupstream of the cannula to ensure that no blood flows back into theaorta during CPB.

The venous drainage cannula(e) is (are) inserted in a similar mannerdirectly through an incision in the right atrium of the heart or intothe superior and/or inferior vena cava for connection to the drainageside of the pump-oxygenator. Once the requisite cannulae are in placeand the connections are made to the heart-lung machine, CPB isinstituted by allowing unoxygenated blood returning to the right side ofthe heart to be diverted through the venous drainage cannula(e) and intothe pump-oxygenator where it is oxygenated and temperature-adjusted.From there, the blood is pumped into the patient's arterial system viathe arterial or aortic perfusion cannula to provide oxygen rich blood tothe patient's body and brain.

After CPB has been established, the process known as cardioplegia, whichliterally means "heart stop," is used to arrest the beating of theheart, and in some procedures, to provide oxygen to the myocardium.Cardioplegia is administered by delivering a cardioplegic solution, suchas potassium, magnesium, procaine, or a hypoclacemic solution, to themyocardium by antegrade and/or retrograde perfusion. For example,cardioplegia may be administered by inserting a needle into the aortaupstream of the aortic cross-clamp and injecting cardioplegic solutioninto the aortic root. The cardioplegic solution drains in the normaldirection of blood flow into the coronary ostia, through the coronaryarteries, and into the capillaries within the myocardium.

The problems with conventional vascular clamps used during the CPBprocess will now be described. As previously mentioned, the vascularcross-clamp is placed externally on the ascending aorta through anincision or opening in the chest. Traditionally, when cardiac proceduresare to be performed, the sternum is cut longitudinally (a mediansternotomy), providing access between opposing halves of the anteriorportion of the rib cage to the heart and other thoracic vessels andorgans. Alternatively, a lateral thoracotomy is formed, wherein a largeincision is made between two ribs. A portion of one or more ribs may bepermanently removed to optimize access. Either of these techniquesprovides a substantial opening in the chest, giving the surgeon arelatively large working area through which to operate.

A problem with these techniques for accessing the heart area is thatthey cause the patient significant trauma. The patient requiresimmediate postoperative care in an intensive care unit, a total periodof hospitalization of up to seven to ten days, and a recovery periodthat can be as long as six to eight weeks.

In more modem, minimally invasive cardiac surgery, smaller incisions aremade in the chest at various strategic locations. The surgicalinstruments are introduced at these locations. An endoscope is providedat one of these locations, and selected surgical instruments aremanipulated by the surgeon with the aid of the endoscope. Accessing theheart area with minimally invasive techniques causes the patient lesstrauma than the techniques described previously.

A problem with all of the aforementioned techniques for accessing theheart area, especially minimally invasive techniques, is that the accessarea or the incision area is very limited in size. The larger and/or thegreater the number of surgical instruments, the more they interfere withthe cardiac procedures to be performed.

Vascular clamps in the past have traditionally had long and/or largeshafts and handles that tend to obstruct the access area during cardiacsurgery. Some vascular clamps in the past have included "bulldog"clamps, or similar clamps, to alleviate this problem. A "bulldog" clampis a small V-shaped clamp that is applied to a blood vessel with anapplier, such as forceps, and left on the blood vessel until it needs tobe removed. Once the "bulldog" clamp is applied to the blood vessel, theapplier is removed from the operating site, reducing the interferingeffect the cross-clamp has on the surgical procedure. A problem with"bulldog" clamps and related clamps is that they do not give theoperator immediate control over the opening and closing of the clamp. Ifthe clamp needs to be opened, an instrument, usually different than theapplier, must be delivered to the surgeon, introduced through theincision, and used to remove the clamp. This opening process takes toolong if blood flow through the clamped blood vessel is immediatelynecessary.

A need therefore exists for a vascular clamp that does not take up asignificant amount of space at the operating site, yet provides theoperator with immediate control over the clamp.

A problem with vascular clamps that relates more to minimally invasivecardiac procedures is that they typically have a construction that makesthem difficult to introduce through a narrow insertion in the chest,and, once in the chest, they are difficult to manipulate around bodytissue to the blood vessel to be clamped.

An additional need therefore exists for a vascular clamp that has aconstruction that facilitates introduction through a narrow insertion inthe chest, and manipulation around tissue within the body to the bloodvessel to be clamped.

In the past, vascular clamps, once they were clamped to the bloodvessel, are usually held in the closed position manually by theoperator, or with a locking mechanism. Manually maintaining the clamp inthe closed position is desirable in that it gives the operator a betterfeel for the pliability of the blood vessel; however, it also introducesthe possibility of operator error. For example, too much pressure on theblood vessel will damage the blood vessel, and insufficient pressurewill not preclude blood flow through the blood vessel. Particularly forclamps without attached handles, quick removal of the clamp is difficultif blood flow through the blood vessel becomes immediately necessary.

Therefore, a further need exists for a vascular clamp that includes alocking mechanism that allows for the immediate release of the clamp.

SUMMARY OF THE INVENTION

An additional aspect of the present invention involves a vascular clampsuitable for temporarily occluding a blood vessel during surgery. Thevascular clamp includes at least one bendable -elongated shaft with aproximal part and distal part. A pair of clamping members are located atthe distal part of the shaft. The clamp includes means for moving theclamping members apart from each other to an open position forsurrounding a portion of the blood vessel and towards each other to aclamping position for compressing the blood vessel with pressuresufficient to occlude blood flow through the blood vessel. After theclamp is applied to the blood vessel, the elongated shaft is bent awayfrom the surgical area of interest, reducing the obstructing effect ofthe vascular clamp on the surgery.

The vascular clamp assembly includes a locking or maintaining meansadapted to maintain the clamping members in the clamping position andmay include a quick release mechanism adapted to disengage the lockingor maintaining means upon actuation of the quick release mechanism,allowing immediate movement of the clamping members.

The at least one bendable elongated shaft may include a pair ofelongated shafts that are slidable lengthwise relative to each androtatable relative to each other. This construction allows one half ofthe vascular clamp to be applied to the blood vessel at a time. Theability to apply one half of the vascular clamp at a time facilitatesintroduction of the vascular clamp through a narrow insertion site, andmanipulation around tissue within the body to the blood vessel to beclamped.

A further aspect of the invention involves a method of temporarilyoccluding a blood vessel during surgery. The method includes a number ofsteps, one of which is providing a vascular clamp with at least onebendable elongated shaft having a proximal part and distal part. A pairof clamping members are located at the distal part of the shaft. Thevascular clamp includes means for moving the clamping members apart fromeach other to an open position and towards each other to a clampingposition. The method also includes the steps of clamping the bloodvessel by compressing the blood vessel with the clamping members withpressure sufficient to occlude body flow through the section, andbending the elongated shaft away from the surgical area of the interestso that the obstructing effect of the vascular clamp on the surgery isreduced.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of the invention will now be described withreference to the drawings of the embodiment, which are intended toillustrate and are not to limit the invention, and in which:

FIG. 1 is a top view of a vascular lamp constructed in accordance withan additional embodiment of the invention, and shows the clamp partiallysurrounding a vessel;

FIG. 2 is a top view of the vascular clamp of FIG. 1, and shows theclamp applied to a vessel and the handle in a bent-away position;

FIG. 3 is a partial, cross-sectional view of a vascular clamp frameconstructed in accordance with an additional embodiment of theinvention, and shows the balloon clamping members in a collapsedcondition;

FIG. 4 is a view, similar to FIG. 3, and shows the balloon clampingmembers in a expanded condition;

FIG. 5 is cross-sectional view taken along lines 11--11 of FIG. 4, andshows the balloon clamping members occluding a vessel;

FIG. 6 is a partial, top view of another embodiment of the frame,showing the balloon clamping members occluding a vessel;

FIG. 7 is a partial, top view of a further embodiment of the frame;showing the balloon clamping members occluding a vessel;

FIG. 8 is a top view of an additional embodiment of the vascular clampof the present invention, and shows the clamp partially surrounding avessel;

FIG. 9 is a top view of the vascular clamp of FIG. 8, and shows theclamp applied to a vessel and the handle in a bent-away position, aswell as showing its proximal inflation device being manually pumped;

FIG. 10 is a cross-sectional view of the vascular clamp handle of FIG. 8taken along lines 16--16 of FIG. 8;

FIGS. 11 and 12 are top views of the vascular clamp of FIG. 8, and showthe clamp being applied to a vessel;

FIG. 13 is a top view of an additional embodiment of the presentinvention;

FIG. 13a is an end view cross-section taken along line A--A in FIG. 13;

FIG. 13b is an end view cross-section taken along line B--B in FIG. 13;

FIG. 13c is an end view cross-section taken along line C--C in FIG. 13;

FIG. 14a and 14b is a detailed cut-away cross-section of the pressurerelief valve for use with the present invention;

FIG. 15 is a top view of a further embodiment of the vascular clamp ofthe present invention, and shows the clamping members in an openposition and partially surrounding a vessel;

FIG. 16 is a top view, similar to FIG. 15, and shows the shaft andhandle in a bent-away position and the clamp applied to the aorta;

FIG. 17 is a partial, top view of a distal portion of the vascular clampof FIG. 15;

FIG. 18 is a top view of an additional embodiment of the vascular clampof the present invention, and shows the clamping members in an openposition, partially surrounding a vessel;

FIG. 19 is partial, perspective view of the distal portion of thevascular clamp of FIG. 28, and shows the clamping members in an openposition;

FIG. 20 is a top view, similar to FIG. 28, and shows the shaft andhandle in a bent-away position and the clamp applied to a vessel; and

FIG. 21 is a partial, side view of the clamp applied to a vessel.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

With reference to FIGS. 1-7 a vascular clamp, indicated generally by thereference numeral 290 and constructed in accordance with an embodimentof the invention, will now be described. The vascular clamp 290 includesan elongated shaft 292 which is preferably bendable with a proximal part294 and distal part 296. The shaft 292 may be a braided or coiled shaftmade of a physiologically acceptable metal or combination of metal andplastic. The shaft construction must be strong enough that it will notbend during insertion and application of the clamp 290, yet malleableenough that it can be bent out of the way of the surgical field withoutendangering the vessel. The shaft 292 includes at least one lumen 298extending the longitudinal distance of the shaft 292.

With reference to FIGS. 1 and 7, the distal part 296 of the shaft 292terminates in a generally U-shaped or C-shaped frame 300. The frame 300includes a pair of prongs 302 joined at a junction 304. The prongs 302and the junction 304 have respective inner wall sections, 306, 308. Theprongs 302 are separated by a distance approximately equal to thediameter of the vessel or organ to be occluded. The frame 300 and theshaft 292 may carry fiber optics (not shown) for transferring light orother information along the thin glass fibers to assist in the cardiacprocedure.

The balloons 310 can be made of one of the polyesters such as PET(polyethelene terephthatate) which is used in balloon angioplastyapplications, one of the polyurethanes, a vinyl material or othersimilar less-elastic material. Even some of the very elastic materialssuch as latex, synthetic latex or silicone may be used if their finalsize is constrained physically by a web or mesh layer. A tubular mesh ofless-elastic material, containing the balloon, and perhaps bonded to it,may also assist in attachment to prongs 302 as well as provide agrip-surface for the balloon/vessel interface. In any configuration, theballoons have a pre-determined expanded size such that they do notexpand beyond a set limit.

The balloons 310 have a high strength and collapse into a low profile.The balloons 310 have a generally circular or oblong cross-sectionalshape; however, other balloon cross-sectional shapes may be used, suchas, but not by way of limitation, rounded-triangular or ribbed. Whenviewing the balloon in a sagittal or side-view section, it follows thecontour of prong 302, whether straight or curved.

It is important for the frame 300 to have a shape that allows thevascular clamp 290 to perform its intended purpose, i.e., occlude thevessel, without disturbing surrounding tissue. FIGS. 3-4 illustrate aframe 300 with a generally geometric configuration that is adapted forsurrounding the aorta, for example, without disturbing surroundingtissue such as the tissue between the pulmonary artery and the aorta. Inthis embodiment, one balloon 310a is larger and has a slightly differentshape than the other balloon 310b. Additionally, the larger balloon 310ais fixed to adjacent inner walls on one side of the frame 300 and thesmaller balloon 310b is fixed to a single inner wall on the oppositeside of the frame 300. FIG. 5 is a cross-sectional view of the clamp290, taken along lines 11--11 of FIG. 4.

FIGS. 6 and 7 illustrate alternative frame embodiments. FIG. 6 shows aframe with a pair of curved prongs having different lengths. FIG. 7shows a frame having a single prong which is more hook-shaped orsickle-shaped. Alternatively, similar to the shaft 292, the frame 300may be made of a bendable material that may be molded to a predeterminedshape that works ideally with a patient's individual tissue geometry.Similar to the shaft 292, the frame 300 must be strong enough that itwill not bend during insertion of the clamp 290, application of theclamp 290 or inflation of the balloons 310, yet malleable enough that itcan be deformed by the operator. They may be malleable only in the planethat is parallel to the long axis of the vessel and the clamp shaft.This would maintain the original distance between the prongs 302.

The balloons 310 are inflatable or expandable by means of a suitablemedium such as air, water, or saline solution. The balloons 310 are influid communication with a fluid supply means via at least one lumen 298(FIGS. 1 and 2). The at least one lumen 298 preferably comprises asingle lumen that extends the length of the shaft 292 and forks at thejunction 304 into a pair of lumens that communicating with a respectiveballoon 310. Alternatively, a pair of lumens may extend the length ofthe shaft 292 with each lumen communicating with a respective balloon310. The proximal part 294 of the shaft 292 includes a fluid supplymeans, such as syringe mechanism 312 having a hollow barrel 314 andplunger 316. The hollow barrel 314 defines a chamber 317, and has aproximal end 318 and distal end 320. The chamber 317 is in fluidcommunication with the at least one lumen 298. The proximal end 318includes a flange 322 and the distal end 320 includes a tapered portion324 with a frustoconical interior 326. The plunger 316 includes aproximal end 328 and a distal end 330. The proximal end 328 includes aflange 332 and the distal end 330 includes a rubber seal 328. Pushingthe plunger 316 causes a fluid such as water or saline to be injectedinto the balloons, expanding the balloons 310. Pulling the plunger 316creating a negative pressure and causing the fluid to re-enter thechamber, collapsing the balloons 310.

Once the balloons 310 are expanded, positive pressure must be maintainedwithin the balloons 310 so that the aorta remains occluded during thecardiac procedure. This may be accomplished in a number of ways, suchas, but not by way of limitation, by providing a detent mechanism, whichprovides sufficient friction in the syringe mechanism 312 between theplunger 316 and the hollow barrel 314 so as to retain the plunger 316 inthe inserted position, i.e. with the balloons 310 expanded, or byproviding a one-way valve, e.g., check valve, that allows fluid to beinjected into the balloons 310, but does not allow fluid to flow backinto the chamber 317 unless the check valve is actuated. Because aone-way valve might not, in some circumstances, allow fluid to leave theballoon 310 quickly enough, the vascular clamp 290 may be configured toreceive a vacuum tube or other device for immediately drawing fluid outof the balloons 310. Alternatively, a simple shut-off valve, manuallyoperated and positioned at the distal end of syringe mechanism couldeffectively control the passage of fluid in lumen 298.

The vascular clamp 290 will now be described in use. If the vascularclamp 290 includes a bendable frame 300, the frame 300 may be deformedby the operator to a shape that is appropriate for occluding thepatient's aorta while not disturbing surrounding tissue. The frame 300is then applied partially around the aorta (FIGS. 1, 3). The plunger 316is pushed into the chamber 317 of the hollow barrel 314, causing thefluid to be injected into the balloons 310 and expand the balloons 310.The balloons 310 serve as clamping members and compress the aorta uponexpansion, occluding blood flow through aorta (FIGS. 2, 4, 5, 6, 7). Thepositive fluid pressure in the balloons 310 is maintained by theaforementioned detent mechanism friction between the plunger 316 andbarrel 314, one-way valve, etc. Maintaining the positive fluid pressurein the balloons 310 effectively locks the balloons 310 on the aorta. Theelongated shaft 292 is bent away from the surgical area of interest oncethe clamp 290 has been applied, reducing the obstructing effect of theclamp 290 on the surgery. If it becomes immediately necessary for theblood to flow through the occluded aorta, withdrawing the plunger 316 ordisengaging the one-way valve causes fluid to flow back into the chamber317, collapsing the balloons 310 so that the aorta is no longeroccluded.

With reference to FIGS. 6-10, a vascular clamp, indicated generally bythe reference number 340 and in accordance with a further embodiment ofthe invention, will now be described. The vascular clamp 340 includes afirst elongated shaft 342 and second elongated shaft 344 that are inmating engagement and are slidable lengthwise relative to each other,and are preferably bendable or malleable. Each shaft 342, 344 hasproximal and distal parts 346, 348, respectively.

With reference to FIG. 10, the first shaft 342 has an arcuate orgenerally C-shaped cross-section 350 that terminates in elongated ends352, and an elongated inner surface 354. A lumen 356 extends the entirelength of the shaft 342.

The second shaft 344 has an elongated main sliding portion 358 with agenerally circular cross-section and an outer surface 360, a supportrail 362 that extends radially from the main sliding portion 358. Alumen 364 extends through the center of the main sliding portion 358 theentire length of the shaft 344. The second shaft 344 slides on its outersurface 360 along the inner surface 354, within the generally C-shapedmember 350. Although the distance between the ends 352 of the C-shapedmember 350 is shown to be approximately the same as the width of therail 362, in an alternative embodiment, the distance between the ends352 may be larger, allowing rotation of the first shaft 342 relative tothe second shaft 344.

Offset frame members 366, 368 are located at the distal parts 348 of therespective shafts 342, 344. Combined, the offset frame members 366, 368form a frame 370. Similar to the frame 300 described above, the framemembers 366, 368 may be deformable. An expandable/collapsible balloon372 is fixed to an inner wall 374 of each frame member 366, 368. Theballoons 372 are in fluid communication with the respective lumens 356,364.

The proximal ends 346 of the respective shafts 342, 344 include slightlycurved handles 376. Each handle 376 carries a squeezeable bladder 378 onone side of the handle 376 and a one-way valve 380 on the other side ofthe handle 376. The squeezeable bladder 378 includes a chamber (notshown) in fluid communication with the respective lumens 356, 364. Theone-way valve 380 allows fluid, e.g., saline, air, etc., in the bladder378 to be transferred to the balloon 372, expanding the balloon 372, andmaintained in the balloon 372 until the one-way valve 380 isde-actuated, allowing the fluid to return to the chamber. Thus, theone-way valve 380 allows for the immediate collapsing of the balloons372. If air is used as the fluid to expand the balloons 372, vents maybe provided that allow air into the bladders 378 and out of the balloons372. Because a one-way valve 380 or vent might not, in somecircumstances, allow the fluid to leave the balloon 372 quickly enough,the vascular clamp 340 may be configured to receive a vacuum tube orother device that draws fluid out of the balloons 372.

With reference to FIGS. 13-14, an alternate embodiment of the presentinvention will be described. The vascular clamp 340 comprises asqueezeable bladder 378 comprised of two chambers, a first 383 incommunication with the one-way valve 380 and a second 385 incommunication with tubular lumen 356, for example. Separating the twolumens inside the bladder 378 is an elastic diaphragm 381 that allowseither lumen to essentially occupy the entire interior space of bladder378 at different times. There is, therefore, one continuous sealedvolume that either fills a balloon 372 or a bladder 378 via thecommunicating tubular lumen 356 within the shaft 342, for example. Thissealed volume is filled with the appropriate volume of liquid, i.e.,saline, and initially occupies the second chamber, the squeezeablebladder 385.

In use, at commencement of vessel occlusion, the squeezeable bladder 385is manually pumped. Every squeeze forces fluid from the second bladderchamber into balloon 372, and every release draws air, being lessviscous, into the first chamber 383 of bladder 378 through the valve380. As can be seen in FIG. 14b, to deflate the balloon, the valve 380can be either opened to allow air to escape or reversed in function topump air out of the first chamber.

The advantageous reasons behind having an instrument with a sealed,fluid-filled operating chamber, filled with sterile saline solution, forexample, that is pressurized with room air are twofold:

1) The part of the instrument that enters the body is filled with afluid that will not injure the patient if ruptured, and,

2) The mechanical requirements of replacing the displaced volume offluid upon inflation and vice versa, is simplified by using theinexhaustible supply of room air.

The vascular clamp 340 will now be described in use. As mentioned above,if the vascular clamp 340 includes a bendable frame 370, the frame 370may be deformed by the operator to a desired shape that is appropriatefor occluding the aorta of the particular patient while not disturbingsurrounding tissue. The frame 370 is then applied partially around theaorta by introducing the offset frame member 368 and collapsed balloon372 of one of the shafts 342, 344 to one side of the aorta (FIG. 11).This is done by sliding and rotating the shaft first applied 342, 344relative to the other shaft 342, 344 so that the offset frame member368, collapsed balloon 372 and shaft 342, 344 are maneuvered through theincision, around body tissue and to the side of the aorta. Because onlyhalf of the vascular clamp 340 has to be inserted and maneuvered at atime, the profile of the clamp 340 is very small. This makes the clamp340 very suitable for manipulating the clamp 340 around body tissue andfor minimally invasive surgery where the incision is small.

The second half of the clamp 340 is then slid into the mating half ofclamp, the distal portion of the second half inserted into the proximalportion of the first half, and rotated into place on the opposite sideof the aorta (FIG. 12). The balloons 372 are expanded by compressing thebladders 378. The balloons 372 serve as clamping members and compressthe aorta upon expansion, occluding blood flow through aorta (FIGS. 9).The positive fluid pressure in the balloons 372 is maintained by theone-way valve 380. The elongated shafts 342, 344 are bent away from thesurgical area of interest once the clamp 340 has been applied, reducingthe obstructing effect of the clamp 340 on the surgery.

If it becomes immediately necessary for the blood to flow through theoccluded aorta, actuating the one-way valve, vent, vacuum means, etc.causes fluid to flow out of each balloon 372, collapsing the balloons372 which open the aorta.

With reference to FIGS. 15-17, a vascular clamp, indicated generally bythe reference numeral 390 and in accordance with an additionalembodiment, will now be described. The vascular clamp 390 includes abendable shaft 392 with a proximal part 394 and a distal part 396. Ahandle 398 is fixed to the proximal part 394 of the shaft 392. A coaxialcompression member 400, preferably a flexible cable with a proximal part402 and a distal part 404 is carried by the shaft 392 and the handle398. A plunger 406 adapted to fit a user's thumb is fixed to theproximal part 402 of the cable 400 by a short, inflexible, extendableshaft 402a.

The distal part 396 of the shaft 392 includes a generally tubular frame408 with a clamping assembly 410 pivotally coupled thereto. Withreference to FIG. 17, a proximal part of the frame 408 has a circularplate 412 with a hole for receiving the cable 400. A distal part of theframe 408 includes a trapezoidal base 414 with an upper face 416 andpair of extensions 418. An inner part of the frame 408 defines acylindrical chamber 420 in which a compression spring 422 is disposed.The compression spring 422 has a predetermined compressive force so thatthe proper closing force is applied to the aorta by the clamp 390. Thecompression spring 422 includes a proximal end 424 and a distal end 426.The spring 422 is supported at its distal end 426 by the upper face 416.The proximal end 424 of the spring 422 abuts a circular flat plate 428of the cable 400. The cable 400 terminates at its distal end in atrapezoidal member 430.

Instead of a cable arrangement, other means for transferring movementand forces from the plunger 406 to the trapezoidal member 430 may beused, such as, but not by way of limitation, a hydraulic arrangement.

The clamping assembly 410 includes a pair of clamping members 432pivotally coupled to the extensions 418 and the trapezoidal member 430.Each clamping member 432 includes a pivoting portion, indicatedgenerally by the reference numeral 434, comprising a first linkage 436and a second linkage 438, and a clamping portion 440. The first linkage436 is generally triangular in shape and is pivotally coupled at aproximal end to the extension 418 at an apex 442 and pivotally coupledto the trapezoidal member 430 at a first vertex 444. The second linkage446 is pivotally coupled at a proximate end to the trapezoidal member430. Together, the pivoting portions 434 form a four-bar linkage.

The clamping portion 440 is pivotally coupled to distal ends of thelinkages 436, 438. The clamping portions 440 move generally parallel toeach other within a generally longitudinal plane defined by the clampingportions 440.

The vascular clamp 390 will now be described in use. With reference toFIGS. 15 and 16, when the plunger 406 is not acted upon, clampingmembers 432 reside in a closed, clamped position. The clamping members432 are maintained in this position by an upward, expanding force of thecompression spring 422 against the circular flat plate 428, as shown bythe arrows in FIG. 17. This upward force causes the trapezoidal member430 to be maintained in an upper position, keeping the clamping portions434 clamped together.

With reference to FIG. 15, downward movement of the cable 400 caused byan operator's thumb pressing or acting on the plunger 406 impartsdownward movement to the trapezoidal member 430 if sufficient pressureis applied. This downward movement causes the clamping portions 434 toopen. The clamp 390 is applied to or removed from the aorta with theclamping portions 440 open. When applying the clamp 390, the aorta ispartially surrounded by the clamping portions 440, and the plunger 406is released, causing the clamping portions 440 to compress the aortawith pressure sufficient to occlude blood flow through the aorta. Thehandle 398 is then bent out of the way from the surgical area ofinterest.

With reference to FIGS. 18-21, a vascular clamp, indicated generally bythe reference numeral 450, and constructed in accordance with anadditional embodiment of the invention, will now be described. Thevascular clamp 450 includes a bendable shaft 452 with a proximal part454 and a distal part 456. A handle 458 is fixed to the proximal part454 of the shaft 452. A coaxial compression cable 460 with a proximalpart 462 and a distal part 464 is carried by the shaft 452 and thehandle 458. A plunger 466 adapted to fit a user's thumb is fixed to theproximal part 462 of the cable 460. The distal part 456 of the shaft 452includes a generally tubular guide frame 467 that guides the cable 460,particularly the otherwise unsupported distal part 464, and a clampingassembly 468.

With reference to FIG. 18, the clamping assembly 468 has a generallyV-shaped configuration and includes a pair of elongated, slightly curvedclamping members 470. The clamping members 470 include respectiveelongated cut-outs 472 and are joined at a pair of vertices 474, whichare fixed to opposite sides of the distal part 456 of the shaft 452.Each cut-out 472 terminates at a distal end near a pin 476. The pin 476is used to pivotally couple a distal end of a respective linkage 478 tothe clamping member 470. The linkages 478 are pivotally coupled at aproximal end to the distal part 474 of the cable 460. A tension spring480 coaxially surrounds the distal part 464 of the cable 460 and isconnected at a proximal end to the frame 467. The distal part of cable464 is a rigid shaft, as it transmits compressive force without thesupport of a cable housing. The tension spring 480 has a predeterminedtension that imparts the proper amount of compression on the aorta.

The vascular clamp 450 will now be described in use. With reference toFIGS. 20, the clamping members 470 reside in a normally closed, clampedposition caused by the tension spring 480 pulling on the proximal endsof the linkages 478. The pulling of the spring 480 causes the clampingmembers 470 to be maintained together.

With reference to FIGS. 18 and 19, pressing or acting upon the plunger466 with sufficient pressure causes the cable 460 to impart movement tothe proximal ends of the linkages 478, opening the clamping members 470.The clamp 450 is applied to, or removed from, the aorta with theclamping members 470 open. When applying the clamp 450, the aorta ispartially surrounded by the clamping members 470, and the plunger 466 isreleased, causing the clamping members 470 to compress the aorta withpressure sufficient to occlude blood flow through the aorta. The handle458 is then bent out of the way from the surgical area of interest toinhibit obstruction with the cardiac procedure.

It will be readily understood by those skilled in the art, that certaincomponents, aspects, principles, etc., of any of the above-describedembodiments, may be applied to other embodiments, such as, but not byway of limitation, the clamp materials, the locking means, the quickrelease mechanism, the clamping assembly, and the manner in which thesize, shape, and configuration of clamping members are moved. Althoughthis invention has been described in terms of a preferred embodiments,other embodiments apparent to those of ordinary skill in the art arealso within the scope of this invention. Accordingly, the scope of thisinvention is intended to be defined only by the claims that follow.

What is claimed is:
 1. A surgical clamp suitable for temporarilyoccluding a vessel during surgery, comprising:at least one bendableelongated shaft, said at least one bendable elongated shaft comprising apair of elongated, bendable shafts and having a proximal part and adistal part, said pair of elongated, bendable shafts being slidablelengthwise relative to each other; a pair of clamping members located atthe distal part of the shaft; and means for moving the clamping membersapart from each other to an open position for surrounding a portion ofthe blood vessel and towards each other to a clamping position forcompressing the blood vessel with pressure sufficient to occlude bloodflow through the blood vessel, whereby said elongated shaft is capableof being bent away from the surgical area of interest, reducing theobstructing effect of the surgical clamp on the surgery.
 2. The surgicalclamp of claim 1, further including a spring that imparts a closingforce on the clamping members.
 3. A surgical clamp suitable fortemporarily occluding a vessel during surgery, comprising:at least onebendable elongated shaft, said at least one bendable elongated shafthaving a proximal part, a distal part, and at least one lumen; a pair ofclamping members located at the distal part, of the shaft, said pair ofclamping members each comprising at least one inflatable balloon, saidat least one inflatable balloon being in fluid communication with saidat least on lumen of said at least one bendable elongated shaft; andmeans for moving the clamping members apart from each other to an openposition for surrounding a portion of the blood vessel and towards eachother to a clamping position for compressing the blood vessel withpressure sufficient to occlude blood flow through the blood vessel,whereby said elongated shaft is capable of being bent away from thesurgical area of interest, reducing the obstructing effect of thesurgical clamp on the surgery.
 4. The surgical clamp of claim 3, whereinsaid shafts are rotatable relative to each other.
 5. The surgical clampof claim 3, wherein each shaft includes a bladder fixed at the proximalpart and a balloon at the distal part, a lumen is carried by theelongated shaft and communicates the bladder with the balloon, a firstshaft has a generally arcuate cross section and an elongated innersurface, a second shaft has a cross section having a configuration formating engagement with the first shaft and an outer surface, and thesecond shaft is slidably received within said other shaft and its outersurface is slidably engaged with the inner surface of the first shaft.6. The surgical clamp of claim 3 wherein the cross-section of the firstshaft is C-shaped and the cross-section of the second shaft is generallycircular.
 7. The surgical clamp of claim 3, further including a springthat imparts a closing force on the clamping members.
 8. The surgicalclamp of claim 3, further including at least one compressible bladderthat is in fluid communication with said at least one lumen forimparting positive fluid pressure to said balloons for expanding theballoons.
 9. The surgical clamp of claim 8, further including a one-wayvalve that is carried by one of the shafts adjacent to the proximal partof the shafts, and the one way valve adapted to immediately reduce thefluid pressure in said balloons.
 10. The surgical clamp of claim 8,wherein said at least one shaft includes a single, elongated shaft, ahandle located at the proximal part of the shaft, and an actuator islocated at the proximal part of the shaft for imparting opening movementto the clamping members.
 11. The surgical clamp of claim 8, wherein saidclamping members include a four bar linkage that is operativelyassociated with a pair of clamping portions, the spring includes acompression spring that imparts a constant closing force on saidclamping portions, said actuator includes a plunger and a coaxial cablethat is coupled at a proximal part to the plunger and at a distal partto the clamping members, and whereby pushing said plunger withsufficient pressure imparts opening movement to said clamping members.12. The surgical clamp of claim 8, wherein said clamping members includerespective elongated clamping portions, the spring includes a tensionspring that imparts a constant closing force on said clamping portions,said actuator includes a plunger and a coaxial cable coupled at aproximal part to the plunger and at a distal part to the clampingmembers, and whereby pushing said plunger with sufficient pressureimparts opening movement on said clamping members.
 13. A method oftemporarily occluding a blood vessel during surgery, comprising thesteps of:providing a vascular clamp comprising at least one bendableelongated shaft with a proximal part and distal part, a pair of clampingmembers located at the distal part of the shaft, and means for movingthe clamping members apart from each other to an open position andtowards each other to a clamping position; clamping the blood vessel bycompressing the blood vessel with the clamping members with pressuresufficient to occlude blood flow through the section; bending theelongated shaft away from the surgical area of interest, reducing theobstructing effect of the vascular clamp on the surgery; providing firstand second elongated shafts, said first and second elongated shaftsbeing slidable lengthwise relative to each other and rotatable relativeto each other, said first and second elongated shafts each having aballoon located at a distal part of said shaft and a bladder located ata proximal part of said shaft, said balloon and said bladder being influid communication with each other through a lumen; and applying theclamp to the blood vessel by manipulating one of the shafts by slidingand rotating it relative to the other shaft and by manipulating theother shaft by sliding and rotating it relative to the first shaft. 14.A method of temporarily occluding a blood vessel during surgery,comprising the steps of:providing a vascular clamp comprising at leastone bendable elongated shaft with a proximal part and distal part, apair of clamping members located at the distal part of the shaft, andmeans for moving the clamping members apart from each other to an openposition and towards each other to a clamping position; clamping theblood vessel by comprising the blood vessel with the clamping memberswith pressure sufficient to occlude blood flow through the section;bending the elongated shaft away from the surgical area of interest,reducing the obstructing effect of the vascular clamp on the surgery;providing a spring, said spring being carried by said at least one shaftand imparting a closing force on the clamping members, an actuator beingcarried by the proximal part of the shaft for imparting opening movementto said clamping members; opening said clamping members by acting uponsaid actuator with sufficient pressure; and relieving pressure on saidactuator so that said spring imparts closing movement to the clampingmembers compressing the blood vessel.